We currently only have one test resource file, sample.coredump.zst, but
the tests for #332 will add more. Create a package, tests.resources, to
contain test resources and a function, get_resource(), to decompress
them. It can also be used on the command line:
python3 -m tests.resources $resource_name
Signed-off-by: Omar Sandoval <osandov@osandov.com>